Modelling on- and off-body channels in Body Area Networks

This paper presents an analysis of the capacity of a 2×2 MIMO system in on- and off-body communications in an indoor multipath environment. The modelling of wearable antennas in Body Area Networks (BANs) has been separated into antennas in the vicinity of the body (full wave simulations), including body dynamics (taken from motion capture analysis), and the environment (clusters of scatterers). A Geometrically Based Statistical Channel model adapted to the BANs environment is used. Based on proper metrics, optimum 2×2 antenna placements are suggested. The best performance is obtained when the on-body sink is on the front and back of the body, and data sensors are on the head, with a capacity gain of 0.97. This sink configuration also enables a good connectivity with an external base station (the capacity gain reaches 0.83).